(function(global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
        typeof define === 'function' && define.amd ? define(factory) :
        (global.Vuex = factory());
}(this, (function() {
    'use strict';

    var devtoolHook =
        typeof window !== 'undefined' &&
        window.__VUE_DEVTOOLS_GLOBAL_HOOK__

    function devtoolPlugin(store) {
        if (!devtoolHook) { return }

        store._devtoolHook = devtoolHook

        devtoolHook.emit('vuex:init', store)

        devtoolHook.on('vuex:travel-to-state', function(targetState) {
            store.replaceState(targetState)
        })

        store.subscribe(function(mutation, state) {
            devtoolHook.emit('vuex:mutation', mutation, state)
        })
    }

    function applyMixin(Vue) {
        var version = Number(Vue.version.split('.')[0])

        if (version >= 2) {
            var usesInit = Vue.config._lifecycleHooks.indexOf('init') > -1
            Vue.mixin(usesInit ? { init: vuexInit } : { beforeCreate: vuexInit })
        } else {
            // override init and inject vuex init procedure
            // for 1.x backwards compatibility.
            var _init = Vue.prototype._init
            Vue.prototype._init = function(options) {
                if (options === void 0) options = {};

                options.init = options.init ? [vuexInit].concat(options.init) :
                    vuexInit
                _init.call(this, options)
            }
        }

        /**
         * Vuex init hook, injected into each instances init hooks list.
         */

        function vuexInit() {
            var options = this.$options
                // store injection
            if (options.store) {
                this.$store = options.store
            } else if (options.parent && options.parent.$store) {
                this.$store = options.parent.$store
            }
        }
    }

    var mapState = normalizeNamespace(function(namespace, states) {
        var res = {}
        normalizeMap(states).forEach(function(ref) {
            var key = ref.key;
            var val = ref.val;

            res[key] = function mappedState() {
                var state = this.$store.state
                var getters = this.$store.getters
                if (namespace) {
                    var module = this.$store._modulesNamespaceMap[namespace]
                    if (!module) {
                        warnNamespace('mapState', namespace)
                        return
                    }
                    state = module.state
                    getters = module.context.getters
                }
                return typeof val === 'function' ?
                    val.call(this, state, getters) :
                    state[val]
            }
        })
        return res
    })

    var mapMutations = normalizeNamespace(function(namespace, mutations) {
        var res = {}
        normalizeMap(mutations).forEach(function(ref) {
            var key = ref.key;
            var val = ref.val;

            val = namespace + val
            res[key] = function mappedMutation() {
                var args = [],
                    len = arguments.length;
                while (len--) args[len] = arguments[len];

                return this.$store.commit.apply(this.$store, [val].concat(args))
            }
        })
        return res
    })

    var mapGetters = normalizeNamespace(function(namespace, getters) {
        var res = {}
        normalizeMap(getters).forEach(function(ref) {
            var key = ref.key;
            var val = ref.val;

            val = namespace + val
            res[key] = function mappedGetter() {
                if (!(val in this.$store.getters)) {
                    console.error(("[vuex] unknown getter: " + val))
                }
                return this.$store.getters[val]
            }
        })
        return res
    })

    var mapActions = normalizeNamespace(function(namespace, actions) {
        var res = {}
        normalizeMap(actions).forEach(function(ref) {
            var key = ref.key;
            var val = ref.val;

            val = namespace + val
            res[key] = function mappedAction() {
                var args = [],
                    len = arguments.length;
                while (len--) args[len] = arguments[len];

                return this.$store.dispatch.apply(this.$store, [val].concat(args))
            }
        })
        return res
    })

    function normalizeMap(map) {
        return Array.isArray(map) ?
            map.map(function(key) { return ({ key: key, val: key }); }) :
            Object.keys(map).map(function(key) { return ({ key: key, val: map[key] }); })
    }

    function normalizeNamespace(fn) {
        return function(namespace, map) {
            if (typeof namespace !== 'string') {
                map = namespace
                namespace = ''
            } else if (namespace.charAt(namespace.length - 1) !== '/') {
                namespace += '/'
            }
            return fn(namespace, map)
        }
    }

    function warnNamespace(helper, namespace) {
        console.error(("[vuex] module namespace not found in " + helper + "(): " + namespace))
    }

    /**
     * forEach for object
     */
    function forEachValue(obj, fn) {
        Object.keys(obj).forEach(function(key) { return fn(obj[key], key); })
    }

    function isObject(obj) {
        return obj !== null && typeof obj === 'object'
    }

    function isPromise(val) {
        return val && typeof val.then === 'function'
    }

    function assert(condition, msg) {
        if (!condition) { throw new Error(("[vuex] " + msg)) }
    }

    var Module = function Module(rawModule, runtime) {
        this.runtime = runtime
        this._children = Object.create(null)
        this._rawModule = rawModule
    };

    var prototypeAccessors$1 = { state: {}, namespaced: {} };

    prototypeAccessors$1.state.get = function() {
        return this._rawModule.state || {}
    };

    prototypeAccessors$1.namespaced.get = function() {
        return !!this._rawModule.namespaced
    };

    Module.prototype.addChild = function addChild(key, module) {
        this._children[key] = module
    };

    Module.prototype.removeChild = function removeChild(key) {
        delete this._children[key]
    };

    Module.prototype.getChild = function getChild(key) {
        return this._children[key]
    };

    Module.prototype.update = function update(rawModule) {
        this._rawModule.namespaced = rawModule.namespaced
        if (rawModule.actions) {
            this._rawModule.actions = rawModule.actions
        }
        if (rawModule.mutations) {
            this._rawModule.mutations = rawModule.mutations
        }
        if (rawModule.getters) {
            this._rawModule.getters = rawModule.getters
        }
    };

    Module.prototype.forEachChild = function forEachChild(fn) {
        forEachValue(this._children, fn)
    };

    Module.prototype.forEachGetter = function forEachGetter(fn) {
        if (this._rawModule.getters) {
            forEachValue(this._rawModule.getters, fn)
        }
    };

    Module.prototype.forEachAction = function forEachAction(fn) {
        if (this._rawModule.actions) {
            forEachValue(this._rawModule.actions, fn)
        }
    };

    Module.prototype.forEachMutation = function forEachMutation(fn) {
        if (this._rawModule.mutations) {
            forEachValue(this._rawModule.mutations, fn)
        }
    };

    Object.defineProperties(Module.prototype, prototypeAccessors$1);

    var ModuleCollection = function ModuleCollection(rawRootModule) {
        var this$1 = this;

        // register root module (Vuex.Store options)
        this.root = new Module(rawRootModule, false)

        // register all nested modules
        if (rawRootModule.modules) {
            forEachValue(rawRootModule.modules, function(rawModule, key) {
                this$1.register([key], rawModule, false)
            })
        }
    };

    ModuleCollection.prototype.get = function get(path) {
        return path.reduce(function(module, key) {
            return module.getChild(key)
        }, this.root)
    };

    ModuleCollection.prototype.getNamespace = function getNamespace(path) {
        var module = this.root
        return path.reduce(function(namespace, key) {
            module = module.getChild(key)
            return namespace + (module.namespaced ? key + '/' : '')
        }, '')
    };

    ModuleCollection.prototype.update = function update$1(rawRootModule) {
        update(this.root, rawRootModule)
    };

    ModuleCollection.prototype.register = function register(path, rawModule, runtime) {
        var this$1 = this;
        if (runtime === void 0) runtime = true;

        var parent = this.get(path.slice(0, -1))
        var newModule = new Module(rawModule, runtime)
        parent.addChild(path[path.length - 1], newModule)

        // register nested modules
        if (rawModule.modules) {
            forEachValue(rawModule.modules, function(rawChildModule, key) {
                this$1.register(path.concat(key), rawChildModule, runtime)
            })
        }
    };

    ModuleCollection.prototype.unregister = function unregister(path) {
        var parent = this.get(path.slice(0, -1))
        var key = path[path.length - 1]
        if (!parent.getChild(key).runtime) { return }

        parent.removeChild(key)
    };

    function update(targetModule, newModule) {
        // update target module
        targetModule.update(newModule)

        // update nested modules
        if (newModule.modules) {
            for (var key in newModule.modules) {
                if (!targetModule.getChild(key)) {
                    console.warn(
                        "[vuex] trying to add a new module '" + key + "' on hot reloading, " +
                        'manual reload is needed'
                    )
                    return
                }
                update(targetModule.getChild(key), newModule.modules[key])
            }
        }
    }

    var Vue // bind on install

    var Store = function Store(options) {
        var this$1 = this;
        if (options === void 0) options = {};
        assert(Vue, "must call Vue.use(Vuex) before creating a store instance.")
        assert(typeof Promise !== 'undefined', "vuex requires a Promise polyfill in this browser.")

        var state = options.state;
        if (state === void 0) state = {};
        var plugins = options.plugins;
        if (plugins === void 0) plugins = [];
        var strict = options.strict;
        if (strict === void 0) strict = false;

        // store internal state
        this._committing = false
        this._actions = Object.create(null)
        this._mutations = Object.create(null)
        this._wrappedGetters = Object.create(null)
        this._modules = new ModuleCollection(options)
        this._modulesNamespaceMap = Object.create(null)
        this._subscribers = []
        this._watcherVM = new Vue()

        // bind commit and dispatch to self
        var store = this
        var ref = this;
        var dispatch = ref.dispatch;
        var commit = ref.commit;
        this.dispatch = function boundDispatch(type, payload) {
            return dispatch.call(store, type, payload)
        }
        this.commit = function boundCommit(type, payload, options) {
            return commit.call(store, type, payload, options)
        }

        // strict mode
        this.strict = strict

        // init root module.
        // this also recursively registers all sub-modules
        // and collects all module getters inside this._wrappedGetters
        installModule(this, state, [], this._modules.root)

        // initialize the store vm, which is responsible for the reactivity
        // (also registers _wrappedGetters as computed properties)
        resetStoreVM(this, state)

        // apply plugins
        plugins.concat(devtoolPlugin).forEach(function(plugin) { return plugin(this$1); })
    };

    var prototypeAccessors = { state: {} };

    prototypeAccessors.state.get = function() {
        return this._vm.$data.state
    };

    prototypeAccessors.state.set = function(v) {
        assert(false, "Use store.replaceState() to explicit replace store state.")
    };

    Store.prototype.commit = function commit(_type, _payload, _options) {
        var this$1 = this;

        // check object-style commit
        var ref = unifyObjectStyle(_type, _payload, _options);
        var type = ref.type;
        var payload = ref.payload;
        var options = ref.options;

        var mutation = { type: type, payload: payload }
        var entry = this._mutations[type]
        if (!entry) {
            console.error(("[vuex] unknown mutation type: " + type))
            return
        }
        this._withCommit(function() {
            entry.forEach(function commitIterator(handler) {
                handler(payload)
            })
        })
        this._subscribers.forEach(function(sub) { return sub(mutation, this$1.state); })

        if (options && options.silent) {
            console.warn(
                "[vuex] mutation type: " + type + ". Silent option has been removed. " +
                'Use the filter functionality in the vue-devtools'
            )
        }
    };

    Store.prototype.dispatch = function dispatch(_type, _payload) {
        // check object-style dispatch
        var ref = unifyObjectStyle(_type, _payload);
        var type = ref.type;
        var payload = ref.payload;

        var entry = this._actions[type]
        if (!entry) {
            console.error(("[vuex] unknown action type: " + type))
            return
        }
        return entry.length > 1 ?
            Promise.all(entry.map(function(handler) { return handler(payload); })) :
            entry[0](payload)
    };

    Store.prototype.subscribe = function subscribe(fn) {
        var subs = this._subscribers
        if (subs.indexOf(fn) < 0) {
            subs.push(fn)
        }
        return function() {
            var i = subs.indexOf(fn)
            if (i > -1) {
                subs.splice(i, 1)
            }
        }
    };

    Store.prototype.watch = function watch(getter, cb, options) {
        var this$1 = this;

        assert(typeof getter === 'function', "store.watch only accepts a function.")
        return this._watcherVM.$watch(function() { return getter(this$1.state, this$1.getters); }, cb, options)
    };

    Store.prototype.replaceState = function replaceState(state) {
        var this$1 = this;

        this._withCommit(function() {
            this$1._vm.state = state
        })
    };

    Store.prototype.registerModule = function registerModule(path, rawModule) {
        if (typeof path === 'string') { path = [path] }
        assert(Array.isArray(path), "module path must be a string or an Array.")
        this._modules.register(path, rawModule)
        installModule(this, this.state, path, this._modules.get(path))
            // reset store to update getters...
        resetStoreVM(this, this.state)
    };

    Store.prototype.unregisterModule = function unregisterModule(path) {
        var this$1 = this;

        if (typeof path === 'string') { path = [path] }
        assert(Array.isArray(path), "module path must be a string or an Array.")
        this._modules.unregister(path)
        this._withCommit(function() {
            var parentState = getNestedState(this$1.state, path.slice(0, -1))
            Vue.delete(parentState, path[path.length - 1])
        })
        resetStore(this)
    };

    Store.prototype.hotUpdate = function hotUpdate(newOptions) {
        this._modules.update(newOptions)
        resetStore(this)
    };

    Store.prototype._withCommit = function _withCommit(fn) {
        var committing = this._committing
        this._committing = true
        fn()
        this._committing = committing
    };

    Object.defineProperties(Store.prototype, prototypeAccessors);

    function resetStore(store) {
        store._actions = Object.create(null)
        store._mutations = Object.create(null)
        store._wrappedGetters = Object.create(null)
        store._modulesNamespaceMap = Object.create(null)
        var state = store.state
            // init all modules
        installModule(store, state, [], store._modules.root, true)
            // reset vm
        resetStoreVM(store, state)
    }

    function resetStoreVM(store, state) {
        var oldVm = store._vm

        // bind store public getters
        store.getters = {}
        var wrappedGetters = store._wrappedGetters
        var computed = {}
        forEachValue(wrappedGetters, function(fn, key) {
            // use computed to leverage its lazy-caching mechanism
            computed[key] = function() { return fn(store); }
            Object.defineProperty(store.getters, key, {
                get: function() { return store._vm[key]; },
                enumerable: true // for local getters
            })
        })

        // use a Vue instance to store the state tree
        // suppress warnings just in case the user has added
        // some funky global mixins
        var silent = Vue.config.silent
        Vue.config.silent = true
        store._vm = new Vue({
            data: { state: state },
            computed: computed
        })
        Vue.config.silent = silent

        // enable strict mode for new vm
        if (store.strict) {
            enableStrictMode(store)
        }

        if (oldVm) {
            // dispatch changes in all subscribed watchers
            // to force getter re-evaluation.
            store._withCommit(function() {
                oldVm.state = null
            })
            Vue.nextTick(function() { return oldVm.$destroy(); })
        }
    }

    function installModule(store, rootState, path, module, hot) {
        var isRoot = !path.length
        var namespace = store._modules.getNamespace(path)

        // register in namespace map
        if (namespace) {
            store._modulesNamespaceMap[namespace] = module
        }

        // set state
        if (!isRoot && !hot) {
            var parentState = getNestedState(rootState, path.slice(0, -1))
            var moduleName = path[path.length - 1]
            store._withCommit(function() {
                Vue.set(parentState, moduleName, module.state)
            })
        }

        var local = module.context = makeLocalContext(store, namespace)

        module.forEachMutation(function(mutation, key) {
            var namespacedType = namespace + key
            registerMutation(store, namespacedType, mutation, path)
        })

        module.forEachAction(function(action, key) {
            var namespacedType = namespace + key
            registerAction(store, namespacedType, action, local, path)
        })

        module.forEachGetter(function(getter, key) {
            var namespacedType = namespace + key
            registerGetter(store, namespacedType, getter, local, path)
        })

        module.forEachChild(function(child, key) {
            installModule(store, rootState, path.concat(key), child, hot)
        })
    }

    /**
     * make localized dispatch, commit and getters
     * if there is no namespace, just use root ones
     */
    function makeLocalContext(store, namespace) {
        var noNamespace = namespace === ''

        var local = {
            dispatch: noNamespace ? store.dispatch : function(_type, _payload, _options) {
                var args = unifyObjectStyle(_type, _payload, _options)
                var payload = args.payload;
                var options = args.options;
                var type = args.type;

                if (!options || !options.root) {
                    type = namespace + type
                    if (!store._actions[type]) {
                        console.error(("[vuex] unknown local action type: " + (args.type) + ", global type: " + type))
                        return
                    }
                }

                return store.dispatch(type, payload)
            },

            commit: noNamespace ? store.commit : function(_type, _payload, _options) {
                var args = unifyObjectStyle(_type, _payload, _options)
                var payload = args.payload;
                var options = args.options;
                var type = args.type;

                if (!options || !options.root) {
                    type = namespace + type
                    if (!store._mutations[type]) {
                        console.error(("[vuex] unknown local mutation type: " + (args.type) + ", global type: " + type))
                        return
                    }
                }

                store.commit(type, payload, options)
            }
        }

        // getters object must be gotten lazily
        // because store.getters will be changed by vm update
        Object.defineProperty(local, 'getters', {
            get: noNamespace ? function() { return store.getters; } : function() { return makeLocalGetters(store, namespace); }
        })

        return local
    }

    function makeLocalGetters(store, namespace) {
        var gettersProxy = {}

        var splitPos = namespace.length
        Object.keys(store.getters).forEach(function(type) {
            // skip if the target getter is not match this namespace
            if (type.slice(0, splitPos) !== namespace) { return }

            // extract local getter type
            var localType = type.slice(splitPos)

            // Add a port to the getters proxy.
            // Define as getter property because
            // we do not want to evaluate the getters in this time.
            Object.defineProperty(gettersProxy, localType, {
                get: function() { return store.getters[type]; },
                enumerable: true
            })
        })

        return gettersProxy
    }

    function registerMutation(store, type, handler, path) {
        var entry = store._mutations[type] || (store._mutations[type] = [])
        entry.push(function wrappedMutationHandler(payload) {
            handler(getNestedState(store.state, path), payload)
        })
    }

    function registerAction(store, type, handler, local, path) {
        var entry = store._actions[type] || (store._actions[type] = [])
        entry.push(function wrappedActionHandler(payload, cb) {
            var res = handler({
                dispatch: local.dispatch,
                commit: local.commit,
                getters: local.getters,
                state: getNestedState(store.state, path),
                rootGetters: store.getters,
                rootState: store.state
            }, payload, cb)
            if (!isPromise(res)) {
                res = Promise.resolve(res)
            }
            if (store._devtoolHook) {
                return res.catch(function(err) {
                    store._devtoolHook.emit('vuex:error', err)
                    throw err
                })
            } else {
                return res
            }
        })
    }

    function registerGetter(store, type, rawGetter, local, path) {
        if (store._wrappedGetters[type]) {
            console.error(("[vuex] duplicate getter key: " + type))
            return
        }
        store._wrappedGetters[type] = function wrappedGetter(store) {
            return rawGetter(
                getNestedState(store.state, path), // local state
                local.getters, // local getters
                store.state, // root state
                store.getters // root getters
            )
        }
    }

    function enableStrictMode(store) {
        store._vm.$watch('state', function() {
            assert(store._committing, "Do not mutate vuex store state outside mutation handlers.")
        }, { deep: true, sync: true })
    }

    function getNestedState(state, path) {
        return path.length ?
            path.reduce(function(state, key) { return state[key]; }, state) :
            state
    }

    function unifyObjectStyle(type, payload, options) {
        if (isObject(type) && type.type) {
            options = payload
            payload = type
            type = type.type
        }
        return { type: type, payload: payload, options: options }
    }

    function install(_Vue) {
        if (Vue) {
            console.error(
                '[vuex] already installed. Vue.use(Vuex) should be called only once.'
            )
            return
        }
        Vue = _Vue
        applyMixin(Vue)
    }

    // auto install in dist mode
    if (typeof window !== 'undefined' && window.Vue) {
        install(window.Vue)
    }

    var index = {
        Store: Store,
        install: install,
        version: '2.1.1',
        mapState: mapState,
        mapMutations: mapMutations,
        mapGetters: mapGetters,
        mapActions: mapActions
    }

    return index;

})));